Customs had a critical role in checking ships and their crew for disease. Passengers and crew often carried diseases from overseas.
One of the museum's images shows a revenue cutter flying signal flags to a newly arrived ship on the River Clyde. The flags state "Are you healthy?"
'Revenue Cutter on the Clyde' by Robert Salmon (1826), with the flag signal for 'Are you healthy?' Source: 'Marine Art and the Clyde' by AS Davidson, © Jones Sands Publishing.
An oath was sworn on the quarantine bible about the health of a ship and her crew. A pole or rope was used to pass the bible from the officer to the ship's captain. The bible was protected in a metal cover. It was thought that the bible would be cleansed by its passage back through salty water to the customs officer.
A pratique (or certificate) was issued if the ship was healthy. The ship was then cleared to enter port. If diseased the vessel was escorted to a quarantine station, and kept in isolation for up to 40 days. There have been various stations on the River Mersey, the most recent was at New Ferry.
There was a strong fear of disease. This can be seen by the heavy penalties. In 1891 if a customs officer knowingly bordered a diseased vessel, the punishment could be 6 months in prison, or a £300 fine (£13,000 in today's money).
Detail of the flags signalling 'Are you healthy?' from 'Revenue Cutter on the Clyde' by Robert Salmon (1826). Source: 'Marine Art and the Clyde' by AS Davidson, © Jones Sands Publishing.
Quarantine bible accession number CENM2001.497.1-2